US3843837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for generating sample pulses in a telephone image transmission system
Assignee: RCA Corp
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Filing: 1973-08-10
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Granted: 1974-10-22
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Expires: 1993-08-10
Abstract
Abstract A frame of stored video information may be considered to comprise a matrix of columns and rows. Correct transmission of this information requires that the sampling of the video elements, column-by-column and row-by-row, be precisely carried out. Two constructions are herein described as employing digital techniques in order to sequentially transmit the information elements along a voice-grade telephone line to be reproduced in a picture display.
Inventors
- 👤 R Hopkins
- 👤 D Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:37
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/12; H04N7/122; H04N7/125
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
210 words
In a television image transmission system of the type wherein an audio communications link is employed to transmit a particular frame of television information to a remote receiver location, apparatus for generating sampling pulses to sequentially transmit said frame information column-by-column and row-by-row, comprising: means for supplying a pulse train of given frequency; means responsive to said pulse train for providing first pulses at a repetition rate determined by the number of columns of information elements into which said television frame is divided and by the number of rows of informational elements within each column; means responsive to said first pulses for providing second pulses at a reduced repetition rate to substantially match with the bandwidth characteristics of said communications link; and logic means actuated by said pulse train and by said second pulses to generate said output sampling pulses for said television information, said logic means including a flip-flop stage settable to a first conductive state by said second pulses and re-settable to a second conductive state by that cycle of pulse train information next succeeding it in time, said logic means further including a pulse counter operative to generate said sample pulses only during those time intervals during which said flip-flop stage is in said second conductive state.
Claim 2
Dependent Claim
210 words
In a television image transmission system of the type wherein an audio communications link is employed to transmit a particular frame of television information to a remote receiver location, apparatus for generating sampling pulses to sequentially transmit said frame information column-by-column and row-by-row, comprising: means for supplying a pulse train of given frequency; means responsive to said pulse train for providing first pulses at a repetition rate determined by the number of columns of information elements into which said television frame is divided and by the number of rows of informational elements within each column; means responsive to said first pulses for providing second pulses at a reduced repetition rate to substantially match with the bandwidth characteristics of said communications link; and logic means actuated by said pulse train and by said second pulses to generate said output sampling pulses for said television information, said logic means including a flip-flop stage settable to a first conductive state by said second pulses and re-settable to a second conductive state by that cycle of pulse train information next succeeding it in time, said logic means further including a pulse counter operative to generate said sample pulses only during those time intervals during which said flip-flop stage is in said second conductive state.
Claim 3
Dependent Claim
72 words
The apparatus of claim 1 wherein said logic means also includes an AND circuit having a first input terminal coupled to receive said pulse train, a second input terminal controlled to enable or inhibit said circuit as a function of the conductive state of said flip-flop stage, and an output terminal coupled to apply said pulse train information to said pulse counter when said flip-flop stage is in said second conductive state.
Claim 4
Dependent Claim
44 words
The apparatus of claim 2 wherein said first pulse providing means provides its pulses at a repetition rate corresponding to the division of said television frame into a matrix of 512 columns of information elements with 525 rows of informational elements in each column.
Claim 5
Dependent Claim
20 words
The apparatus of claim 3 wherein said pulse train supply means supplies a train of pulses of 8 MHz frequency.
Claim 6
Dependent Claim
55 words
The apparatus of claim 4 for use in a television image transmission system utilizing an unequalized voice-grade television line having a bandwidth of 2 kHz as its said audio communications link, wherein said second pulse providing means provides its pulses at substantially one-eighth the repetition rate of pulses provided by said first pulse providing means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |